The Deer Lick Cluster is in the upper left. NGC 7331 is the larger spiral galaxy in the upper left. NGC 7331 has been called the Milky Way’s Twin but more recent data has shown that the Milky Way is a barred spiral galaxy and so it isn’t an apt comparison. NGC 7331 is about 40 million light years away and receding from us at 816 km/s.
The galaxies to the top of it are actually more distant galaxies and not gravitationally associated with NGC 7331. They are 300-350 million light years away.
Stephan’s Quintet is the cluster of galaxies in the lower right hand corner. Four of the five galaxies are gravitationally interacting but the fifth is just photobombing the group. The galaxy at the top and most seperated from the group, NGC 7320C, is the interloper. It is actually much closer to us than the other four. It might actually be part of the NGC 7331 group (it is about the same distance from us). The other four members of the quintet are 210-340 million light years away.
The wispy light colored strands wandering throug the image are integrated flux nebula. This is dust outside our galaxy that is reflecting the combined light of our galaxy back at us (that’s what makes it “integrated flux”). This stuff is seriously faint and has been significantly enhanced to make it visible next to the galaxies. In reality it is much, much fainter than the galaxies. Some of that faint fuzzy stuff near the galaxy is from tidal tails…streams of stars that have been pulled out by the interacting gravity of the galaxies.
This is 40 hours of LRGB data.
You can find all the technical details at astrobin.